Rotary jar-type well tool



INVENTOR.

WILLIS F. ORR, BY

films AT TQRNEY.

United States Patent 3,316,986 ROTARY JAR-TYPE WELL TOOL Willis P. Orr,Tyler, Tex., assignor, by mesne assignments, to Esso Production ResearchCompany, Houston, Tex., a corporation of Delaware Filed Mar. 22, 1965,Ser. No. 441,752 4 Claims. (Cl. 175-297) This invention relates to welltools for imparting a rotary jar or impact to a pipe string or tool thathas become jammed in a well bore so as to free the pipe string or toolso that it can be recovered.

Pipe strings become jammed in wells for a number of reasons, such asdifferential pressure sticking, cave-ins, and pipe failures throughdeterioration thereof. Sometimes the torque on the pipe string can beincreased to the point where the pipe string or tool can be freed, or ajar can be applied at the earths surface to the same end. Generallyspeaking, however, it has been found to be more etficacious to connect arotary jarring device to the stuck pipe string as near thereto aspossible in the hole so that the force resulting from the jar or impactwill not lower portion of the mandrel.

be absorbed in the relatively long pipe string extending to the earthssurface. Rotary jarring devices known to the prior art for the most partmake use of vertical reciprocation of the upper pipe string to effectthe jar. The impact force produced by such devices is necessarilylimited. One object of the present invention is to produce a rotary jardevice capable of producing an extremely high impact force.

Objects and features of the invention not apparent from the abovediscussion will become evident upon consideration of the followingdescription of the invention when taken in connection with theaccompanying drawings, wherein:

FIG. 1 is a side View, partially in cross section, illustrating apreferred embodiment of the invention;

FIG. 2 is a sectional view taken along section 22 of FIG. 1,illustrating the component parts of the apparatus of FIG. 1 in oneoperative position thereof;

FIG. 3 is a sectional view similar to FIG. 2 illustrating the componentparts of the apparatus of FIG. 1 in another operative position thereof;and

FIG. 4 is an enlarged sectional view of a portion of the apparatus.

Briefly described, the present invention comprises a mandrel adapted tobe coupled to an upper pipe string section and a sleeve sectionextending around the lower portion of the mandrel and adapted to beconnected to a lower pipe string section. Segmental hammer spline meansis provided on the mandrel and radially extends therefrom. An internalcavity or keyway in the sleeve section accommodates the hammer splinemeans and is considerably larger than the hammer spline means. Thecavity is comprised of two portions of different diameters, the firstportion having a diameter which is in snug fit with the hammer splinemeans for permitting only restricted liquid passage therebetween, andanother portion of a diameter much greater than the diameter of thespline means and mandrel for permitting substantially unimpeded fluidmovement therebetween. The cavity forms an anvil shoulder for receptionof blows from the hammer. Means are provided for holding the hammer awayfrom the anvil until large torque can be exerted on the mandrel so thatthe hammer will strike the anvil shoulder with great force, which willbe transmitted to the lower pipe string section.

With reference now to FIG. 1, there is shown an elongated mandrel 1including an upper coupling member 5 having tapered threads thereon forconnection to an upper pipe string section which extends to the earthssurface through a borehole. Suitable apparatus for exerting rotarytorque on the drill string, such as rotary drilling 3,316,986 PatentedMay 2, 1 967 "ice apparatus, is connected to the upper end of the drillstring. A bore 2 may extend through the mandrel for circulation ofdrilling fluid if such be desired. An annular bearing member 25 isconnected to or is integral with the mandrel near the lower end thereof.

An elongated sleeve member comprising a plurality of sections 3, 9, and29 is provided with an elongated bore therethrough, at least a portionof which is greater than the outside diameter of the greater portion ofthe mandrel 1, so that the sleeve section extends around the The lowermandrel section 29 is provided with a screw-threaded projection 37similar to connecting section 5 for connecting the sleeve sections to atool or lower pipe string section which is assumed to have been stuck inthe well. Manifestly, other constructions for connecting two lower pipestring sections may be used. The lower sleeve section 29 isscrewthreadedly connected to the middle sleeve section 3. Bearingmembers 27 and 23 are respectively positioned below and above themandrel bearing 25 so as to support the weight of the mandrel and thepipe string sections thereabove so that the mandrel can rotate withinthe sleeve sections. The upper sleeve section 9 is provided with asleeve bearing 15 to permit the mandrel to rotate within the sleevesections without binding.

A spline means or hammer 17 is aflixed to or integral with mandrel 1between sleeve bearing 15 and bearing 23. The hammer 17 may be describedas segmental and is of a suflicient size to strike a hard blow againstanvil shoulder 20 without being broken off of mandrel 1. The hammerrotates within a cavity formed within the sleeve section 3, which cavityhas a section 22 which is of a radius substantially that of the curvedouter surface of hammer 17. Thus, as the hammer rotates within thecavity section 22, only a restricted amount of fluid will pass betweenthe wall of the cavity section 22 and the curved outer surface of thehammer 17. The cavity has a section 18 which is of substantially greaterradius than the radius of section 22 so that the hammer can rotatefreely therethrough and fluid can flow freely therearound. A passagewaycomprising sections 19 and 24- extends through the hammer section 17, asshown in FIG. 2. The passageway section 19 is of substantially greaterdiameter than the diameter of section 24, and the two sections are ofsubstantially circular cross section with a tapered portioninterconnecting them so as to form a seat for a ball 26 which is heldwithin the passageway section 19 by one or more small projections 28that permit liquid to flow around the ball and out of the passageway.Thus, when the mandrel is rotated counterclockwise, as shown by thearrow 30, the ball 26 will seat so as to prevent passage of fluidthrough the passageway. The ball 26 may be held against the seat bymeans of a light compression spring, as shown in FIG. 4, or thepassageway may be drilled on an incline extending downwardly from thelarger opening 19. However, whenthe mandrel is rotated clockwise, theball will be unseated so that fluid can flow therearound and the mandrelcan be freely turned. a

The liquid within the cavity sections 22 and 18 may be water, oil,hydraulic fluid, or other suitable liquid. The liquid is held within thecavity by seals 21, 11, and 13, the seals 11 and 21 being between thesleeve and the mandrel, and the seal 13 being between sleeve sections 3and 9. Seals 35 and 33 are provided to prevent Well fluid from damagingthe bearings 23, 25, and 27.

Let it be assumed that the sleeve section 29 has been connected to astuck pipe string or tool in the lower end of a well bore. When a largetorque is exerted on the upper pipe string section connected to themandrel 1 by suitable equipment at the earths surface, the mandrel willturn very slowly within the sleeve member as fluid flows between thecurved outer surface of hammer 17 and the sleeve section wall defined bycavity section 22. As soon as the hammer passes out of the cavitysection 22, the hammer will turn rapidly and strike anvil shoulder 20with great force. This operation can be repeated as many times as isnecessary until the stuck pipe string section or tool has been jarredloose.

Manifestly, by obvious and appropriate design changes, the invention canbe used to jar by exerting torque in a clockwise direction.

The invention is not necessarily to be restricted to the specificstructural details or arrangement of parts herein set forth, as variousmodifications thereof may be effected without departing from the spiritand scope of the invention.

What is claimed is:

1. Apparatus for connection to a drill string for imparting a rotary jarto a drill string section in the lower end of a borehole, comprising:

an elongated mandrel;

means for coupling said mandrel to an upper pipe strin section;

a sleeve section extending around the lower portion of said mandrel;

means for connecting said sleeve section to a lower pipe string section;

hammer spline means on said mandrel radially extending therefrom;

an internal cavity in said sleeve section for accommodating said hammerspline means; said cavity having a portion of a first diameter in snugfit with said hammer spline means for permitting restricted liquidpassage therebetween, said cavity having a portion of a second diametergreater than said first diameter for permitting substantially unimpededfluid movement therebetween, and forming an anvil shoulder for receptionof blows from said hammer spline means; sealing means between saidmandrel and sleeve sections for preventing escape of fluid in saidcavity; and

passageway means including check valve means in said hammer spline meansfor permitting free fluid flow therebetween only when said hammer splinemeans is turned away from said anvil shoulder.

2. Apparatus for connection to a drill string for imparting a rotary jarto a drill string section in the lower end of a borehole, comprising:

an elongated mandrel;

means for coupling said mandrel to an upper pipe string section;

a sleeve section extending around the lower portion of said mandrel;

means f or connecting said sleeve section to a lower pipe stringsection;

hammer spline means on said mandrel radially extending therefrom;

an internal cavity in said sleeve section for accommodating said hammerspline means, said cavity forming an anvil shoulder for reception ofblows from said hammer spline means; and

means for holding said hammer spline means away from said anvil untillarge torque is exerted on said mandrel.

3. Apparatus for connection to a drill string for irn parting a rotaryjar to a drill string section in the lower end of a borehole,comprising:

an elongated mandrel;

means for coupling said mandrel to an upper pipe string section;

a sleeve section extending around the lower portion of said mandrel;

means for connecting said sleeve section to a lower pipe string section;

hammer spline means on said mandrel radially extending therefrom;

an internal cavity in said sleeve section for accommo dating said hammerspline means, said cavity forming an anvil shoulder for reception ofblows from said hammer spline means; and

means for permitting substantially unimpeded movement of said hammerspline means in said cavity away from said shoulder, said cavity havingsubstan tially the same internal diameter as the external diameter ofsaid hammer spline means and mandrel to restrict fluid passagetherebetween over an arc of predetermined magnitude to permit torquebuildup on said mandrel.

4. Apparatus for connection to a drill string for imparting a rotary jarto a drill string section in the lower end of a borehole, comprising:

an elongated mandrel;

means for coupling said mandrel to an upper pipe string section;

a sleeve section extending around the lower portion of said mandrel;

means for connecting said sleeve section to a lower pipe:

string section;

hammer spline means on said mandrel radially extending therefrom;

an internal cavity in said sleeve section for accommodating said hammerspline means;

said cavity having a portion of a first diameter in snug fit with saidhammer spline means for permitting restricted liquid passagetherebetween, said cavity having a portion of a second diameter greaterthan said first diameter for permitting substantially unimpeded fluidmovement therebetween, and forming an anvil shoulder for reception ofblows from said hammer spline means;

sealing means between said mandrel and sleeve sections for preventingescape of fluid in said cavity;

passageway means including check valve means in said hammer spline meansfor permitting free fluid flow therebetween only when said hammer splinemeans is turned away from said anvil shoulder;

an annular bearing affixed to said mandrel below said hammer splinemeans; and

a sleeve bearing in said sleeve section above said hammer spline meansfor engaging said mandrel.

References Cited by the Examiner UNITED STATES PATENTS 1,944,481 1/1934Wells 293 X 2,708,100 5/1955 Sutliif 175-299 X 2,988,147 6/1961 Webb175--297 X 3,200,895 8/1965 Womack 175306 X CHARLES E. OCONNELL, PrimaryExaminer.

D. H. BROWN, Assistant Examiner.

2. APPARATUS FOR CONNECTION TO A DRILL STRING FOR IMPARTING A ROTARY JARTO A DRILL STRING SECTION IN THE LOWER END OF A BOREHOLE, COMPRISING: ANELONGATED MANDREL; MEANS FOR COUPLING SAID MANDREL TO AN UPPER PIPESTRING SECTION; A SLEEVE SECTION EXTENDING AROUND THE LOWER PORTION OFSAID MANDREL; MEANS FOR CONNECTING SAID SLEEVE SECTION TO A LOWER PIPESTRING SECTION; HAMMER SPLINE MEANS ON SAID MANDREL RADIALLY EXTENDINGTHEREFROM; AN INTERNAL CAVITY IN SAID SLEEVE SECTION FOR ACCOMMODATINGSAID HAMMER SPLINE MEANS, SAID CAVITY FORMING AN ANVIL SHOULDER FORRECEPTION OF BLOWS FROM SAID HAMMER SPLINE MEANS; AND MEANS FOR HOLDINGSAID HAMMER SPLINE MEANS AWAY FROM SAID ANVIL UNTIL LARGE TORQUE ISEXERTED ON SAID MANDREL.